Use our free Pet Calorie Calculator to estimate daily energy needs for dogs and cats. Enter weight, pick species and life stage/activity to get RER and MER (kcal/day).
Daily Energy Needs (RER & MER)
Type to calculate – results update instantly.
- RER = 70 × (body weight in kg0.75). This is the baseline energy need at rest.
- MER = RER × activity/life-stage factor (neutered adult, intact, growth, weight loss, etc.).
- These are estimates. Health status, environment, breed and body condition can shift real needs.
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Understanding Pet Calorie Needs
Every dog or cat requires the right amount of calories each day to stay healthy, maintain an ideal body weight, and support growth or activity. Veterinarians usually calculate energy needs using Resting Energy Requirement (RER) and Maintenance Energy Requirement (MER).
What Is RER?
The Resting Energy Requirement represents the energy needed for essential body functions while at rest, such as breathing, circulation, and digestion. The formula is simple:
RER = 70 × (body weight in kg0.75)
More details can be found on Wikipedia (Basal Metabolic Rate) .
What Is MER?
The Maintenance Energy Requirement is based on RER multiplied by an activity or life-stage factor. For example, a neutered adult dog may need around ×1.6 RER, while a growing puppy may need up to ×3 RER. Similarly, an indoor neutered cat may only require ×1.2 RER. You can read veterinary guidelines from the AAHA Nutrition Guidelines.
Why Balanced Calories Matter
- Weight control: Overfeeding leads to obesity, underfeeding causes malnutrition.
- Life stage support: Puppies and kittens need more calories for growth, while senior pets usually require less.
- Activity: Active pets, working dogs, or outdoor cats burn more calories daily.
For more practical information on daily feeding, see PetMD: Dog Calorie Needs.
Using the Pet Calorie Calculator
With this calculator, you can quickly enter your pet’s weight, select species, and choose activity level to estimate RER and MER. Results are shown instantly, making it easy to plan meals, treats, or weight management programs. Always confirm with your veterinarian before changing your pet’s diet.
Try more free tools: Dog Age Calculator · Cat Age Calculator · All Pet Calculators.